Optically-readable disk with copy protection device

ABSTRACT

An optically-readable disk includes a device that disrupts readability of the disk when the disk is spun at an angular velocity substantially greater than required to play the disk in its intended playing device, or for when a defined integral of velocity and time is exceeded. The device may include a fluid container that disperses a data-disruptive fluid. The device may include a membrane or layer that is disrupted when the disk is rotated above a defined angular velocity, or when a defined integral of velocity and time is exceeded.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optically readable disk designed toinhibit the copying of the content recorded on it by being renderedunreadable when read at any speed higher than the disk's standardplayback speed.

2. Background of the Invention

Optically-read disks present a common and popular way of storing dataand other content. Specifically, consumer entertainment content in theform of movies, music and other media are commonly recorded on disks andsold to consumers. Optically-read disks include, for example, audio CDs,CD-ROMs, and DVDs.

Unfortunately, the content recorded on optically-read disks can beillegally reproduced in violation of copyright laws. Such unauthorizedreproduction is especially widespread due to the increasing availabilityand affordability of equipment used to reproduce the content recorded onan optically-read disk.

There have been various attempts to inhibit such copying, the majorityof which focus on various encryption methods designed to preventcopying. In addition, some optical disks may be protected by means ofnoncontiguous data files separated by barriers designed to interrupt adisk player's reading of the disk.

Previous security devices and techniques aimed at preventing the illegalcopying of protected content recorded on optically-readable disks,besides being expensive to implement, have focused on methods toovercome, and stay one step ahead of, disk player and disk recordingtechnology. Unfortunately, as the security features implemented toprevent illegal copying becomes more sophisticated, they are quicklyrendered obsolete due to the continuing and rapid advancement of diskrecording technology. Accordingly, there is a need for an optical diskhaving a copy protection feature which overcomes the aforementioneddeficiencies of the prior art.

SUMMARY OF THE INVENTION

The present invention is directed to an optically-readable disk havingprotection against unauthorized reproduction of the data recorded on thedisk.

When a user inserts a disk into a disk player for viewing of the data,the disk player spins the disk at a speed sufficient to enable the diskplayer to read the data so the user can view the content recorded on thedisk. A typical commercially-available disk player intended solely forthe purpose of viewing disk content, for example, a DVD player that isconnected to a television, reads the disk at the slowest speed possiblefor playback and viewing.

Other disk players that are widely available, for example, thoseavailable as a component of a home computer system, routinely spin thedisk at speeds much higher than what is required for the disk player tosimply read the disk content for playback. These high speed disk playersallow users, in conjunction with disk recording hardware, to copy thedisk content in a much shorter time period than what would be requiredif the user were to attempt to copy the disk while the disk was spinningat the slower playback speed.

Accordingly, if a user wished to make a copy of a disk, the user wouldnaturally use a readily available and inexpensive disk reader that wouldspin the disk at a higher rate of speed than the slower playback speed.This allows the user to copy the disk content in a much shorter timeperiod. It also provides a user easy means to pirate copyrightedmaterial by making multiple copies of the disk for illegal distribution.For example, it would take a copier two hours to copy a two hour movierecorded on a DVD where the disk was spinning at normal playback speed.However, a user could copy the same two hours worth of content in lessthan 10 minutes if the disk reader spun the disk at higher speeds.

The present invention is designed to frustrate a user's ability to copythe content of the disk by only allowing the disk to be read at theslower playback speed. If the disk is read at the faster “copying”speed, the disk is rendered unreadable and copying is thwarted.

In an embodiment of the invention, an optically-readable disk contains asmall capsule or container attached to or embedded in its readingsurface. The capsule or container is designed and attached to the diskso as not to interfere with a disk reader's reading of the disk and soas not to interfere with the stable spinning of the disk while beingplayed. The capsule contains an obscuring compound such as ink or otheropaque or reflective fluid. The capsule's membrane is constructed of amaterial that remains stable at low “read-only” or “playback” speeds.However, if the disk is inserted into a disk player and the disk is spunat speeds higher than the minimum speed necessary to read the disk andplayback the disk content, the material of the capsule will disintegrateor otherwise destabilize. As a result, the capsule will fail and releaseits contents onto the reading surface of the disk, obscuring the readingsurface and rendering the disk unreadable by the disk reader.

In another embodiment of the invention, a deformable membrane isattached to the reading surface of the disk in such a manner to permitreading of the disk at slow, playback speeds. When the disk is spun atspeeds higher than the playback speeds, the membrane deforms. Thisprevents the disk content from being read by the disk reader.

In another embodiment of the invention, a deformable membrane isattached to either surface of the disk so as to permit reading of thedisk at slow, playback speeds. However, when the disk is spun at speedshigher than the playback speeds, the membrane expands either above thesurface of the disk or beyond the edges of the disk so as to physicallyinterfere with the disk player's components, thus rendering the diskunplayable by the disk player.

In another embodiment of the invention, a thin membrane is adhered tothe reading surface of the disk using an adhesive such that, when thedisk spins in the disk reader at slow, playback-only speeds, themembrane remains uniformly adhered to the reading surface of the diskand does not interfere with reading data on the disk. However, if thedisk player spins the disk at speeds higher than slow, playback-onlyspeeds, the resulting forces may cause the adhesive to fail or introducediscontinuities in the membrane surface which causes the membrane toreflect or obscure the reading surface of the disk in a manner whichrenders the disk unreadable.

A more complete understanding of the method and system for preventingthe copying of an optically-readable disk will be afforded to thoseskilled in the art, as well as a realization of additional advantagesand objects thereof, by a consideration of the following detaileddescription of the preferred embodiment. Reference will be made to theappended sheets of drawings which will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a breakaway plan view showing a planar structure of anoptically-readable disk 100, according to a first preferred embodimentof the invention showing the fluid containing container 101, attached tothe disk surrounding the drive rotation hole, 102, of the disk.

FIG. 1B is a planar view of the fluid containing container configured ina toroid shape to accommodate attachment of the container on the diskaccording to the first preferred embodiment of the invention.

FIG. 2 is a breakaway plan view showing an alternative embodiment havinga fluid-containing container located near the rim of anoptically-readable disk.

FIG. 3 is a sectional structure view of the optically-readable diskshowing the plurality of layers of the disk, including a deformationlayer according to an embodiment of the invention.

FIG. 4 is a sectional structure of an optically-readable disk accordingto a embodiment of the invention showing a membrane layer adhered to thedisc.

FIG. 5 is an enlarged view of a container showing the suspension ofmicrospheres within the fluid contained in the container, configured topenetrate the container membrane when the container is subjected tosufficient centrifugal force.

FIG. 6 shows an exemplary fluid container including a structure forfluidic integration of centrifugal force over time.

FIG. 7 is a block diagram showing a configuration for a circuitactivated penetrating member attached to the container membrane andconfigured to pierce the container membrane upon the detection ofsufficient, sustained centrifugal forces.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is particularly applicable to the prevention ofthe copying of optical disks, for example, CD, CD-ROM, DVD, DVD-ROM,HD-DVD, or Blu-Ray™ disks. Specifically, optical disks are primarilypurchased (or rented) by users for playback of content encoded on thedisk to produce audio-visual output on a user's television using a DVD,HD-DVD or Blu-Ray™ player, to produce music output on the user's musicplayer, to play a game using the user's game player, and so forth. Whenused for this purpose, the receiving end-user player will spin theoptical disk only at the slow, playback speed. If a user wishes to makean illegal copy of optical disk content, the user would insert theoptical disk into a disk player that would spin the disk at speeds muchfaster than playback speeds used for simple viewing of the encoded diskcontent. In the detailed description that follows, like element numeralsare used to indicate like elements appearing in one or more of thefigures.

FIG. 1A illustrates a first preferred embodiment of the invention.Specifically, it shows a planar structure of an optically-readable disk100 with a toroid shaped container 101, attached to the center of thedisk surrounding the drive rotation hole 102 of the disk. Thisembodiment permits a disk player to spin the disk without anyinterference from the container. This embodiment also permits the diskplayer to read the data reading area 104, without interference from thecontainer. The data reading area 104 may include encoded digital datadesigned to be read by an optical pick-up device and decoded by a playerto produce audio-visual, audio, or visual output for human consumptionor to provide software for operation by a computer.

As used herein, a “readable” disk or area is one that may have itsmicroscopic encoded digital data read by an optical pick-up device foruse in an electronic player or computer. It should be apparent thatoptical disks may also include printed surfaces and labels designed tobe read by the human eye; as used herein, a readable surface does notinclude these types of printed surfaces and labels.

When the container is subjected to angular velocities substantiallygreater than an angular velocity corresponding to a playback speed ofthe optical disk, the container may rupture, leak, or allow its contentsto diffuse into an interior of the disk. The placement of the container100 in this embodiment may allows for the container to be subject tosuch angular velocities upon the spinning of the disk substantiallyfaster—for example, at least 50% or 100% faster—than needed for playingthe disk in a CD player, DVD player, or the like. Also, in thisembodiment, the placement of the container provides an effective meansfor the release and disbursement of the fluid 112 (as shown in FIG. 2)onto the data reading area upon the container membrane's 110 collapse(as shown in FIG. 1B). This disbursement of the fluid onto the datareading area thus interferes with the disk player's reading of the datarecorded on the disk and therefore prevents copying of the data recordedon the disc.

Optionally, released fluid may be distributed into an interior of thedisk via one or more transparent channels 105. Released fluid maycomprise a gas or liquid. The released fluid may itself be opaque orreflective, or may cause a latent material distributed over a surface ofthe disk to become opaque or reflective. In the alternative, or inaddition, the fluid may comprise a reactive material that reacts withmaterials in the disk's optically-readable layer to destroy or degradereadability of the disk, or the structural integrity of the disk.Preferably, the released liquid remains contained inside the disk afterit is released from its container, or is of a nature so as to not harmadjacent people, devices, clothing, or the like, if released from thedisk. Fluid-containing structures in an interior of a disk may bestructured so that fluid of a certain viscosity will not flow into anarea where data will be rendered unreadable unless the disk is spun fora prolonged period of time that is much longer than normal playing time,is spun at velocities exceeding normal playback velocity, or comecombination of the foregoing. In addition, fluid-containing structuresmay be configured so that fluid will out of data areas to an originationregion if the disk is handled in a certain fashion. For example, fluidmay flow out of data areas if the disk is stored on edge for a prolongedperiod of time. Such a configuration may permit functioning of a disk tobe restored after data is temporarily obscured.

FIG. 2 shows an alternative embodiment comprising a fluid 152 containedin a container 153 near an outer rim 157 of an optically-readable disk150. Container 153 may be disposed adjacent a puncturing structure 155,which may comprise, for example, one or more small teeth or needlesconfigured to puncture the container walls. When disk 150 is spun atnormal playing speed, the centrifugal force acts on the container 153 inthe direct indicated by arrow 156. However, the container andsurrounding structures are configured such that the centrifugal forcedoes not puncture or otherwise unseal the container. At substantiallyhigher speeds, however, the container may be pressed against cuttingteeth 155 or similar structure, releasing the fluid 152 into an interiorof the disk, e.g., via a channel or partially open layer.

FIG. 3 shows a sectional structure of the disk in an alternativeembodiment of the invention. Specifically, an optically-readable disc100 may be generally constructed of a plurality of layers, including atop layer 200, which comprises the top of the disk, anoptically-readable layer 201 upon which the data is recorded, as well asa reflective layer 202 and a transparent layer 204 both of whichfacilitate a disk player's reading of the data recorded on theoptically-readable layer of the disk.

A deformation layer 203 may be interposed between the reflective layerand transparent layer. This deformation layer may be constructed of amaterial that is stables and permits a disk reader to read the datarecorded on the optically-readable layer 201 when the disk is repeatedlyspun at an angular velocity no greater than for normal playback in aconsumer viewing device. When the disk is spun at an angular velocitysubstantially greater than the angular velocity required to read thedata for playback in an end-user device, the deformation layer 203 maycavitate, crack, craze, deform, or otherwise alter itslight-transmitting or reflecting properties, thereby disrupting orinterfering with the disk reader's ability to read the data recorded onthe disk. Based on this second preferred environment, the deformationlayer can accomplish this disruption or interference by partially orentirely obscuring the optically-readable layer, whichoptically-readable layer is positioned behind the deformation layer. Inaddition, disruption of the reading of the disk can be accomplished byhaving the deformation layer deform or stretch beyond the edges of thedisk thus causing physical interference with the disk reader.

Another embodiment has the deformation layer secured to either thebottom of the transparent layer 204 or top layer 200. In thisembodiment, the deformation layer is configured so that when it deforms,it can expand beyond the physical boundaries of the disk. Again, thepurpose of such deformation is to physically interfere with the diskreader and thus prevent the reading of the disk.

In an embodiment of the invention, the deformation layer may comprise anelastic material or a visco-elastic material with a shape memory. Afterdeforming during excessively high-speed rotation, the layer may returnto its original configuration after the disk stops spinning, such as bylying the disk on a flat surface. Restoration of the original shape mayoccur relatively quickly, for example, in less than one minute or lessthan one hour, or relatively slowly, for example, longer than one houror longer than one day. In addition, or in the alternative, it may bepossible to restore the deformation layer by exposure to a certainenvironment, for example, to an elevated temperature, infrared orultraviolet radiation, or by exposure to a specific liquid or gas. Thismay permit the functioning of disks to be restored after acopy-protection feature is activated.

FIG. 4 shows another alternative embodiment of the invention wherein amembrane layer 205 may be adhered to the transparent layer 204. Themembrane layer may include an adhesive that is configured to bond themembrane layer to the transparent layer at slow, disk reading speeds.When the disk is spun at angular velocities substantially greater thanthe disk reading speed, the adhesive fails causing the membrane layer toseparate from the transparent layer. Such separation may obscure theoptically-readable layer 201 or will otherwise interfere with the discreader's ability to read the data recorded on the optically-readablelayer.

Whether a container with fluid or a deformation layer is used, theselectively-obscuring element should be more sensitive to centrifugalforces and less so to forces acting in other directions, for example,such as may arise from flexing the disk during handling or accidentallydropping the disk. A material, container, or device may be used that isnot activated by impulses or forces acting for a relatively shorterperiods of time. For example, in an embodiment of the invention, thedisk may include an electronic, micro-mechanical, or fluidic device thatintegrates excess centrifugal force over time. Centrifugal force below adefined threshold and non-centrifugal forces may be ignored by thedevice, but centrifugal forces above a defined threshold are integratedover time until a triggering threshold is reached. For example, amicro-fluidic device may be configured such that centrifugal force abovea defined threshold causes a fluid to flow through an orifice into acontainer. Surface tension of the fluid prevents flow when centrifugalforce is below the threshold level. When the container is full, thedevice triggers activation of the obscuring device. Electrical ormechanical analogs of fluidic force-integrating devices may also beused.

The use of a force-integrating activation device may also be used toconfigure a disk so that it is rendered unreadable if spun even atrelatively low velocities, i.e., normal playback speeds, for more than adefined period of time. For example, a disk could be designed to remainreadable for a single play, or for any number of plays, after which itis rendered unreadable. However, because a force-time integral is usedas the triggering factor, the disk may remain readable for any desiredlength of time under the control of the disk consumer, if it is not spunat all or is not spun for longer than the defined time.

FIG. 5 shows any exemplary structure of a container and contained fluidsuch as may be used in the embodiments exemplified by FIGS. 1A and 2,and that may be configured to integrate centrifugal force. Specifically,the container 100 may contain a fluid 102, such as an ink or solvent,configured for obscuring or otherwise rendering unreadable the readingsurface of the disk upon its release from the container. Microspheres103 may be suspended in the contained fluid, configured to degrade themembrane 101 of the container when they come in contact with themembrane. Under sufficient and sustained centrifugal force, sufficientnumbers of microspheres should come into contact with the membrane,causing the membrane to rupture, leak or otherwise release the fluidonto the disk. Container 100 may be configured with one or moredepressions or pockets 117 in the radial direction that graduallycollect microspheres when the container is subjected to centrifugalforce above a defined threshold. Below the threshold, the viscosity offluid 102 may prevent migration of microspheres to the membrane walls.After a sufficient number of microspheres have collected near a membranewall, the membrane may rupture, releasing fluid 102.

FIG. 6 shows a portion of an exemplary container 101 incorporating afluidic structure configured to integrate centrifugal force over time.Container 101 may be located near or in the hub of an optically-readabledisk 100, and may be generally toroid in shape. The fluidic structuremay comprise one or more nozzles 120 or openings in the membrane wall110. Fluid 112 and openings 120 may be configured such that, due to thesurface tension and viscosity of fluid 112 and the configuration of eachopening 120, the fluid will not pass out of the container thorough theopening unless the disk 100 is spinning at an angular velocitysubstantially greater than the normal playback velocity.

The fluidic structure may further comprise a channel 122 through whichfluid 112 must pass before it reaches and corrupts the encoded-dataportion 104 of disk 100. The channel may be provided between disk layersand be generally closed along its length and open at both ends. Anynumber of channels may be provided to allow for fluid communicationbetween each opening and the encoded area 104. The channel may have anysuitable cross-section, interior surface properties and length so as toslow droplets or steams of fluid passing through the opening and preventfluid from reaching the encoded data until the disk 100 has been spunfor a defined integral of angular velocity and time. For example, thechannel may be designed so that fluid exiting the nozzles 120 does notreach the data area 104 until the disk has been spun for a period oftime greater than, for example, one second, ten seconds, one minute, tenminutes, one hour, ten hours, or one-hundred hours at a normal playbackvelocity, and for correspondingly less time at greater velocities.Channel 122 may be provided in a linear, serpentine, labyrinth, coil, orany other desired course. It should be apparent that purelyvelocity-sensitive triggering devices and time-velocity sensitivedevices may be combined in a single device.

In an embodiment of the invention, channel 122 and a fluid-containingportion of data area 104 may be configured so that fluid can flow backthrough the channel and into container 101 after it has been released.For example, the disk may include a funnel-shaped transition channelconnecting a distal end of channel 122 to the data area 104. Fluidreleased into the data area may then be funneled back into the channelby setting the disk on edge, so that gravity acts to pull released fluidback into the channel and container. This may permit functioning of thedisk to be restored after a release event. In this embodiment, nozzle120 may permit bidirectional flow of fluid, i.e., in or out of container101. In the alternative, nozzle 120 may be omitted.

FIG. 7 provides an illustration, in the form of a block diagram, of anadditional disk or method for causing the rupture of a fluid containeror other activation of a data-corrupting system. Specifically, acircuit-activated penetrating member system comprising a power source303, a force detecting sensor 302, an actuator 301 and penetratingmember 300 may attached to the membrane 110 of a container 101. Theseelements may be incorporated into a very small electronic device andsecured to the disk, for example, by an adhesive label or by holdinginto the disk hub. The penetrating member 300 may be positioned adjacentto the membrane 110 so as to rupture the membrane when activated. Theforce detecting sensor 302 may measure any centrifugal force applied tothe system as a result of the spinning of the disk, to which the system,through the container, is attached. The sensor 302 may also beconfigured to measure the sustained duration of any such centrifugalforce. When the sensor 302 detects a sufficient centrifugal force ofsufficient duration, it signals the actuator 301 which activates thepenetrating member 300 which ruptures the membrane.

According to the foregoing, therefore, an optical disk may be configuredwith one of the foregoing containers, layers, membranes, or devicesconfigured to render encoded data on the disk unreadable if the disk isspun at an angular velocity substantially greater than a playbackangular velocity used for normal reading of the encoded data by an enduser device, for example, by a CD player, an DVD player, a HD-DVDplayer, or a Blu-Ray™ player, to produce an audio-visual output. In anembodiment of the invention, the container, layer, membrane or device isconfigured to render the disk unreadable if the disk angular velocityexceeds the playback angular velocity by at least 50%. In otherembodiments, the container, layer, membrane or device may be configuredto render the disk unreadable if the disk angular velocity exceeds theplayback angular velocity by one of at least 100%, 500%, 1000%, 1500%,2000%, or 2500%. In the alternative, or in addition, the container,layer, membrane or device may be configured to render the diskunreadable if the disk angular velocity exceeds the playback angularvelocity by at least any of the foregoing thresholds or by any amountfor a period of time, or by an integral of angular velocity and time. Inthe alternative, the container, layer, membrane or device may beconfigured to render the disk unreadable if the disk angular velocitydoes not exceed the playback angular velocity, but if the integral ofangular velocity and time exceeds a defined threshold, to provide a diskthat that cannot be spun and remain readable for more than a limitedamount of playing time.

Having thus described an embodiment of an optically-readable diskdesigned to inhibit the copying of the content recorded on it byrendering the disk unreadable at a speed substantially higher than thedisk's standard playback speed, it should be apparent to those skilledin the art that certain advantages of the within system have beenachieved. It should also be appreciated that various modifications,adaptations, and alternative embodiments thereof may be made within thescope and spirit of the present invention. The invention is defined bythe following claims.

1.-8. (canceled)
 9. An optically-readable disk comprising: a plurality of layers, including an optically-readable data layer having data encoded therein; a deformation layer disposed over the data layer, the deformable layer comprised of a material that does not interfere with reading of the data layer when the disk is spun at a first angular velocity suitable for playback, and that deforms so as to interfere with reading of the data layer when the disk is spun at a second angular velocity, substantially greater than the first angular velocity.
 10. The optically-readable disk of claim 9, wherein the deformation layer is configured to expand beyond a periphery of the disk when the disk is spun at the second angular velocity.
 11. The optically-readable disk of claim 9, wherein the deformation layer comprises an adhesive material.
 12. The optically-readable disk of claim 9, wherein the deformation layer adheres a membrane layer to the disk.
 13. The optically-readable disk of claim 12, wherein the membrane layer is secured to the top surface of the disk.
 14. The optically-readable disk of claim 12, wherein the membrane is located in the plurality of layers of the optically-readable disk.
 15. The optically-readable disk of claim 9, wherein the deformation layer comprises an elastic material capable of returning to an original condition after deforming.
 16. The optically-readable disk of claim 9, wherein the deformation layer comprises a visco-elastic material having a shape memory property for returning to an original condition after deforming.
 17. The optically-readable disk of claim 9, wherein the deformation layer is configured to return to an original undeformed shape after exposure to a defined environmental condition. 